Mucosal resection device and related methods of use

ABSTRACT

A resection device for resecting tissue from a body. The device includes an elongate member having a proximal end, a distal end, and a lumen extending from the proximal end to the distal end. The device further includes a cap assembly configured 
     to be coupled to the distal end of the elongate member. The cap assembly may include a first cap defining a resection loop channel and a distal end having a first opening. The assembly may further include a second cap configured to receive a portion of the first cap. The second cap includes a distal end having a second opening. A distal portion of the first cap and a distal portion of the second cap may cooperate to define a resection loop track for receiving a resection loop.

PRIORITY

This application is a continuation of U.S. application Ser. No.13/659,760, filed Oct. 24, 2012, now U.S. Pat. No. 9,204,782, whichclaims priority to U.S. Provisional Application No. 61/552,326, filedOct. 27, 2011, all of which are incorporated herein by reference intheir entireties.

FIELD OF THE INVENTION

This disclosure relates generally to systems and methods for resectingtissue. More particularly, embodiments of the claimed invention relateto systems for endoscopic mucosal resection.

BACKGROUND OF THE INVENTION

Organ walls are composed of several layers: the mucosa (the surfacelayer), the submucosal, the muscularis (muscle layer), and the serosa(connective tissue layer). In gastrointestinal, colonic, and esophagealcancer, small polyps or cancerous masses form along the mucosa and oftenextend into the lumens of the organs. Conventionally, that condition hasbeen treated by cutting out a portion of the affected organ wall. Thisprocedure, however, may cause extensive discomfort to patients, andposed health risks. Recently, physicians have adopted a minimallyinvasive technique called endoscopic mucosal resection (EMR), whichremoves the cancerous or abnormal tissues (polyps) or normal tissues,keeping the walls intact.

EMR is generally performed with an endoscope, which is a long, narrowtube equipped with a light, video camera, and channels to receive otherinstruments. During EMR, the endoscope is passed down the throat orguided through the rectum to reach a tissue in the affected organ orotherwise targeted tissue. The distal end of the endoscope, furtherequipped with a cap that has a small wire loop, is guided towards theabnormality. Once there, a suction pump attached to the tube is startedto draw the abnormality towards the endoscope cap. When the tissue issufficiently drawn into the cap, the wire loop closes around the tissue,resecting it from the organ wall. Subsequently, excised tissue may beextracted by, e.g., the vacuum, for examination or disposal.

Certain polyps, such as pedunculated polyps, may be characterized by astalk attached to the mucosal layer. Drawing such polyps into the capwithout drawing in any other tissue is readily accomplished. Certainother polyps, such as sessile polyps, however, may exhibit a broad baseand they lay flat on the mucosal surface, devoid of a stalk. It is oftendifficult to grasp these polyps without drawing in a part of themuscularis layer.

To overcome this problem, saline solution is typically injected beneaththe target tissue to raise the mucosal tissue and create a buffer layer.The raised tissue can then readily be severed with a resection loop,often in several segments (segmental resection) depending on the sizeand location of the tissue.

In addition, the depth of the cut made by the wire loop cautery iscritical. As discussed above, if the cut is too deep, the muscularislayer may be injured, which may further cause a perforation. Conversely,a cut too shallow may not remove enough of the affected tissue andtherefore may require additional procedures or worse, contribute to thedevelopment of metastatic cancer. Typically, more than 2 mm of canceroustissue clearance is required to assure complete removal. EMR, asperformed with conventional devices and methods, may result incomplications such as perforation, bleeding, and/or strictures.

Therefore, there exists a need for an improved endoscopic mucosalresection loop that effectively resects pedunculated and sessile polypsor other tissues without damaging the surrounding tissue or musclelayers of the organ.

SUMMARY OF THE INVENTION

Embodiments of the present disclosure provide a device for resecting anundesired tissue from a patient's body using a minimally invasivesurgical system.

In accordance with an aspect of the present disclosure, a resectiondevice for resecting tissue from a body is described. The deviceincludes an elongate member having a proximal end, a distal end, and alumen extending between the distal end and the proximal end. The devicefurther includes a cap assembly configured to be coupled to the distalend of the elongate member. The cap assembly includes a first capdefining a resection loop channel, wherein the first cap includes adistal end having a first opening. Further, the cap assembly includes asecond cap configured to receive a portion of the first cap. The secondcap includes a distal end that has a second opening, such that thedistal portion of the first cap and a distal portion of the second capcooperate to define a resection loop track for receiving a resectionloop.

In various embodiments, the device may include one or more of thefollowing additional features: the resection loop track and theresection loop channel may be in communication with each other; theresection loop track may be disposed in a plane parallel to a plane ofthe second opening; the resection loop track may extend at an angle tothe resection loop channel; the resection loop channel may furtherinclude a cylindrical section positioned inside the first cap; the firstcap includes a working channel extending from the distal end to theproximal end of the first cap; the resection loop channel may be formedof a flexible wall configured to collapse the resection loop channelwhen a resection loop is not present in the resection loop channel; aportion of the resection loop channel may be configured to preventdistal movement of a sheath associated with a resection loop; and thecap assembly may be configured to pivot relative to the distal end ofthe elongate member.

According to another embodiment, an endoscopic cap configured to besecured to a distal of an introduction sheath is described. Theendoscopic cap includes a first cap defining a resection loop channeland having a distal end having a first opening. The endoscopic capfurther includes a second cap having a distal end having a secondopening. The second cap is configured to receive a portion of the firstcap. Further, a distal portion of the first cap and a distal portion ofthe second cap cooperate to define a resection loop track for receivinga resection loop. The resection loop track may be in communication withthe resection loop channel and disposed in a plane parallel to a planeof the second opening.

In various embodiments, the endoscopic cap may include one or more ofthe following additional features: the first cap includes a workingchannel extending from the distal end to the proximal end of the firstcap; a portion of the resection loop channel is defined by an outer wallof the first cap; the resection loop channel further includes acylindrical section disposed within the first cap; the distal end facesof the first and second caps may be angled relative to a longitudinalaxis of the endoscopic cap: and the resection loop may be anelectrocautery tool.

A further aspect of the present disclosure includes a cap assemblyconfigured to be secured to a distal end of an endoscope. The capassembly may include a first cap defining a resection device channel,wherein the first cap includes a distal end having a first opening. Thecap assembly may also include a second cap configured to receive aportion of the first cap, wherein the second cap includes a distal endhaving a second opening, wherein a distal portion of the first cap and adistal portion of the second cap cooperate to define a resection devicetrack for receiving a resection device.

In various embodiments, the method may include the additional featuresof: the resection device track and the resection device channel may bein communication with each other; the resection device track may extendat an angle to the resection device channel; the cap assembly may beconfigured to pivot relative to the endoscope; and the first cap mayfurther include a working channel extending from the distal end to theproximal end of the first cap.

Additional objects and advantages of the claimed invention will be setforth in part in the description, which follows, and in part will beobvious from the description, or may be learned by practice of theinvention. The objects and advantages of the invention will be realizedand attained by means of the elements and combinations particularlypointed out in the appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of thepresent disclosure and together with the description, serve to explainthe principles of the disclosure.

FIG. 1A is an exploded view of an EMR cap assembly, according to anembodiment of the present disclosure.

FIG. 1B is a sectional view of the EMR cap assembly of FIG. 1A.

FIG. 1C is an end view of the EMR cap assembly of FIG. 1A.

FIG. 2A is a schematic of an inner cap, according to embodiments of thepresent disclosure.

FIG. 28 is an end view of the inner cap of FIG. 2A.

FIG. 2C an isometric view of the inner cap of FIG. 2A taken from theproximal end.

FIG. 2D is an isometric view of the inner cap of FIG. 2A taken from thedistal end.

FIGS. 3A-3C illustrate various embodiments of the inner cap, accordingto embodiments of the present disclosure.

FIG. 4 illustrates the EMR cap assembly of FIG. 1 viewed from the distalend.

FIG. 5 illustrates an exemplary resection device incorporating the EMRcap assembly of FIG. 1, according to embodiments of the presentdisclosure.

FIGS. 6A-6F illustrate an exemplary method for resecting a tissue froman organ's mucosal wall using the EMR cap assembly of FIG. 1, accordingto embodiments of the present disclosure.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to embodiments of the presentdisclosure, an example of which is illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts. The term“distal” refers to the end farthest away from a medical professionalwhen introducing a device in a patient. By contrast, “proximal” refersto the end closest to the medical professional when placing a device inthe patient.

Overview

Embodiments of the present disclosure relate to systems and methods forresecting and extracting foreign or undesirable objects from a patient'sbody. For example, the device may remove cancerous polyps or lesionsfrom the mucosal walls of the colon, esophagus, stomach, duodenum, orany other suitable location. It should be understood that the resectiondevice may perform the functions of both resecting and retrieving, butfor convenience, the term “resection device” will be used throughoutthis application.

The resection device may include an end-effector, such as, e.g., an EMRcap assembly, fitted on the distal end of any tube, such as anendoscope, for ensnaring, cauterizing, and extracting tissue such as apolyp. The EMR cap assembly may include a working channel, as well as aresection loop channel aligned with and inserted into the workingchannel. The EMR cap assembly may further include a track along itsdistal circumference in communication with the resection loop channel,such that a resection loop extending from the resection loop channelslides into the track when the resection loop is in an open position. Inthis position, the resection loop is parallel to the opening of the EMRcap assembly. When the EMR cap assembly is placed over an undesiredtissue, suction can be applied to draw the tissue into the workingchannel. The resection loop may then be pulled proximally, reducing thediameter of the loop in the track and engaging the drawn tissue.Subsequently, the tissue is cauterized and extracted. Because theresection loop is parallel to the EMR cap assembly's distal opening, theoperator can easily place the resection loop around the tissue tocapture and cauterize it. Moreover, only the mass drawn into the EMR capassembly's working channel is resected, ensuring that deeper layers ofthe organ wall are not affected.

In the following sections, embodiments of the present disclosure will bedescribed using an exemplary body organ—the esophagus. It will beunderstood that this choice is merely exemplary and that the device maybe utilized in any other suitable organ, such as the colon, duodenum,stomach, or any other organ that may be subject to polyps, lesions,stones, and the like.

Exemplary Embodiments Exemplary EMR Cap Assembly

FIGS. 1A-1C presents three views of an EMR cap assembly 100 forresecting polyps, lesions, or otherwise unwanted tissue from, e.g., themucosal walls of organs according to embodiments of the presentdisclosure. EMR cap assembly 100 is configured to be secured to a distalportion of an endoscope for advancing towards a target location with apatient. Particularly, FIG. 1A is an exploded view, FIG. 1B is asectional view, and FIG. 1C is an end view of EMR cap assembly 100.These figures will be commonly referenced to describe the structure andfunction of the EMR cap assembly 100. The EMR cap assembly 100 may bedetachably connected to the distal end of any flexible or rigid tube,such as an endoscope used for colonoscopy, resectoscopy, cholangioscopy,or mucosal resection.

EMR cap assembly 100 includes an inner cap 102 and an outer cap 104. Theinner and outer caps 102, 104 may be hollow elongate members with distalends 106, 107, respectively, and proximal ends 108, 109, respectively,with lumens 110, 111, respectively, extending between the respectivedistal and proximal ends. The outer cap 104 fits over the inner cap 102,and this complete assembly is attached to a tube (not shown).

The inner cap 102 and outer cap 104 may have substantially circularcross-sections or cross-sections similar to those of body cavities.Where required by given applications the EMR cap assembly 100 mayinclude elliptical, semi-circular, rhombic, rectangular, or othernon-circular profiles. Moreover, the diameter of the EMR cap assembly100 may vary based on the size of the body lumens in which it operates.For example, if the EMR cap assembly 100 is inserted through theurethra, the diameter of the inner and outer caps may be very small.Conversely, if the device is inserted through the rectum, the diameterof the inner and outer caps may be larger.

Any suitable material may form inner and outer caps 102, 104. Forinstance, rigid or semi-rigid materials such as metals (includingmaterials such as nitinol), polymers, resins, or plastics may be used.Further, a biocompatible material that does not irritate the body lumensmay form a coating or layer over the outer surface of EMR cap assembly100.

A detailed discussion of inner cap 102 and outer cap 104 follows, inconnection with FIGS. 2-4.

FIG. 2 illustrates three views of inner cap 102. More particularly, FIG.2A is a schematic view, FIG. 2B is an end view, FIG. 2C is an isometricview taken from proximal end 108, and FIG. 2D is an isometric view takenfrom distal end 106. Lumen 110 of inner cap 102 includes a workingchannel 202 and a resection loop channel 204. The dimensions of thesechannels may vary considerably from one application to another. Forexample, in procedures where a resected mass is extracted through thetube, working channel 202 may be larger than resection loop channel 204.Otherwise, where no need for removal of a resected mass is presented,resection loop channel 204 may be larger than working channel 202.Moreover, working channel 202 may include numerous other channels tocarry desired instruments, such as cameras, light sources, and otherendoscopic instruments,

As illustrated in FIG. 2A, resection loop channel 204 extends fromproximal end 108 to distal end 106 of inner cap 102. Moreover, aproximal portion of channel 204 may include a hollow or lumenal section206 (FIG. 2C), and this section may lead to a flared section 208 (FIGS.2C and 20) towards the cap's distal end 106.

Section 206 may accommodate an outer sheath of a resection loop (notshown). In one embodiment, the diameter of section 206 is substantiallyequal to or smaller than the diameter of the resection loop sheath.Moreover, section 206 may taper distally such that the diameter of thesection's distal end is smaller than the diameter of the sheath,preventing the sheath from extending beyond the distal end of section206. Alternatively, section 206 may have a uniform diameter from itsproximal to distal end, optionally including a ledge 210 on its distalend. The ledge 210 extends radially inwards, reducing the distal end'sdiameter to equal the sheath's inner diameter, thereby stopping thesheath from extending distally beyond the distal end of section 206. Theshaded portion in FIG. 2B illustrates ledge 210.

It will be understood that instead of the ledge, any other structure maybe employed to reduce the diameter of the cylindrical portion's distalportion. For example, some configurations may include actuatableprotrusions, or barbs extending inwards in parallel to the distal end ofthe section 206.

Flared section 208 does not necessarily flare-out radially in alldirections; instead, it may flare out parallel to a portion of the cap'sinternal wall. In some embodiments, however, section 208 may fully flareout.

A portion or the entire resection loop channel 204 may be in contactwith the inner wall. Alternatively, resection loop channel 204 may bepositioned adjacent the inner wall. In this embodiment, a support block212 may connect resection loop channel 204 with the inner wall. It willbe understood that the resection loop channel's placement within lumen110 may vary without departing from the scope of the present disclosure.

In some instances, section 206 may not abut the inner wall of the innercap 102. Instead, it may be slightly spaced from the inner surface.Flared section 208, however, may make contact with the inner wall.Moreover, the width of flared section 208 may be smaller than or equalto the diameter of section 206. To maintain this width and to increasethe working channel's area, flared section 208 may curve toward theinner wall. FIG. 2A illustrates this embodiment.

Alternatively, the width of flared section 208 may be greater than thediameter of section 206. In this case, the portion of the resection loopchannel wall in contact with working channel 202 may extend parallel tothe longitudinal axis of section 206, while, the portion of the channelwall closer to the inner wall may flare out radially to contact theinner wall. FIGS. 3A and 3B illustrate this embodiment. Compared to FIG.2A, it is evident that this embodiment features a broader resection loopchannel 204, while the working channel 202 space is reduced.

In an alternative embodiment, the portion of the inner cap 102 abuttingflared section 208 may be cut-out or removed, leaving the resection loopchannel with a partial wall. Outer cap 104 abuts flared section 208(FIG. 1A) forming the remaining wall for resection loop channel 204.

The degree of angular displacement of the distal end of flared section208 may vary based on numerous factors, such as tensile strength of theresection loop, size of resection loop, or diameter of inner cap 102. Itwill be understood, however, that flared section 208 may be sufficientlybroad and wide to allow the resection loop to open completely into anactive position. “Active position” refers to a position in which theresection loop is completely open and its loop diameter is approximatelyequal to the diameter of inner cap 102,

Alternatively, resection loop channel 204 may not have a cylindricalsection, and instead, it may begin flaring from the proximal end 108 ofthe inner cap 102 (shown in FIG. 3C). It will be understood that theshape of flared section 208 may vary without departing from the scope ofthe present disclosure. For example, the flare's cross-section may havea generally “U” shape, “V” shape, semicircular shape, semi-ellipticalshape, square shape, rectangular shape, or any suitable shape.

In FIG. 2, resection loop channel 204 is permanently fixed in the innercap and in the gap between the inner and outer caps. In anotherembodiment, however, resection loop channel 204 may be detachablyconnected to working channel 202. When the resection loop is not in use,resection loop channel 204 may be removed. In another embodiment, theresection loop channel 204 may be collapsible, i.e., formed of aflexible membrane. When the resection loop is not inserted in the cap,the flexible membrane may rest against the inner wall of inner cap 102(converting the complete lumen into working channel 202). When theresection loop is inserted, it may push the flexible member away fromthe inner wall and into the working channel 202. Once the lesion isresected, the resection loop may be retracted, and the flexible membermay return to its original position (against the inner wall of inner cap102). Detachably connecting resection loop channel 204 or incorporatingit with a flexible wall increases working channel 202 width, allowingthe resection device to extract large resected pieces.

Outer cap 104 includes a general cross-sectional shape similar to thatof inner cap 102. An inner diameter of outer cap 104, however, is largeenough to fit around inner cap 102. When fit over inner cap 102, distalend 107 of outer cap 104 extends distally beyond inner cap 102. Thespace between the distal ends of inner cap 102 and outer cap 104 mayform a track for guiding the resection loop, such as track 112 shown inFIG. 1B.

FIG. 4 illustrates the track in detail. As shown, track 112 includes thecircular-shaped distal surface of inner cap 102, and the inner walls ofouter cap 104, extending distally beyond inner cap 102. Further, thetrack may be sufficiently wide and high to slidably receive a resectionloop, such as resection loop 402. Moreover, the distal surface of outercap 104 may include a support structure 404 such as an edge, ridge,ledge, or rail extending circumferentially inward such that the supportstructure is wide enough to cover the proximal surface of inner cap 102,thus providing a track surrounded on three sides (top, bottom, and outeredge) and open on one side (inner edge). Alternatively, supportstructure 404 may include multiple equidistant protrusions extendingtowards the lumen 110. These support structures allow the resection loop402 to rest parallel to the distal opening of the EMR cap assembly 100when the resection loop 402 is extended into track 112. It will beunderstood that any other structure to maintain the resection loop 402within track 112 is conceivable and within the scope of the presentdisclosure.

In one embodiment, the distal openings of both inner cap 102 and outercap 104 may lie perpendicular to the longitudinal axes of the caps.Alternatively, the distal openings may slant at an acute angle to thelongitudinal axes. Because tissues may be present on the esophagealwalls, out of the direct path of an endoscope advancing through thatorgan, the slanted distal opening provides a greater surface areacontact between the EMR cap assembly's distal opening and the tissues.It will be understood that the slant angle may vary based on the organor the procedure. For example, a narrower body organ, such as theesophagus, may call for a distal opening slanted at a greater angle thanfor wider body organs, such as the stomach.

Resection loop channel 204, along with track 112, forms a path for theresection loop 402. The loop, enclosed within a sheath, may be insertedfrom the proximal end 108 into the resection loop channel 204. Thesheath may extend up to the distal end of section 206. From there, theresection loop may be advanced distally into the flared section 208.Because the channel 204 is flared, the resection loop is providedsufficient space to expand into the active position. Moreover, flaredsection 208 merges with track 112, allowing the resection loop to slideinto track 112 in its active position, such that the loop rests alongthe circumference of the inner cap's distal opening, between the innerand outer cap.

Pushing the resection loop distally places it in the active position ontrack 112, while pulling the resection loop proximally, closes theresection loop. Because the resection loop lies in track 112, it closesessentially parallel to the distal opening of the EMR cap assembly. Thisresection loop configuration allows the EMR cap assembly to grasp andhold flat tissues.

As described in this disclosure, the resection loop is a wire loopdevice used to cauterize a lesion, polyp, or any other tissue. Thecross-sectional diameter of the wire may vary according to theapplication. In an embodiment, resection loop may be a resecting hook,surrounding a portion of the cap. Further, the resecting hook may haveany cross-sectional geometry. For example, the cross-section may beflat, round, or triangular. In another embodiment, the resection loopmay be a cauterizing resection loop that is energized by passingelectrical energy through the loop. Moreover, the electrical energy maybe sufficient to cauterize the tissue swiftly. The cauterizing resectionloop may be mono-polar where high frequency electrical current is passedfrom a single electrode and the patient's body serves as ground orbipolar where high frequency electrical current is passed through thetissue from one electrode to another. It will be understood that insteadof electrical energy, any other form of energy now known or known in thefuture may be supplied to the resection loop to resect the tissue fromthe organ wall. For example, high heat energy may be supplied, enablingthe resection loop to burn the tissue from the organ wall. Similarly,other energy sources, e.g., RF and cryogenic, may be considered withoutdeparting from the scope of the present disclosure. In addition, thedisclosed EMR cap assembly may be utilized with any suitable cuttingdevice known to those skilled in the art.

The inner and outer caps may be detachably connected, permanentlycoupled, or formed into an integral component. Detachable connectionsmay include, but are not limited to, snap fit assembly, screw fitassembly, luer-lock assembly, or force lock assembly. For example, aproximal portion of the outer cap's inner wall may include one or morescrew threads, while the corresponding portion of the inner cap's outerwall may include corresponding screw threads. After placing outer cap104 over inner cap 102, the outer cap 104 may be rotated to engage thescrew threads of the inner and outer caps 102, 104. In another instance,inner cap 102 may include one or more protrusions along its outer wall,while outer cap 104 may include corresponding grooves on its inner wall.The protrusions may engage with the grooves when outer cap 104 is placedover inner cap 102, snap fitting them in place. It will be understoodthat other temporary connection techniques are well within the scope ofthe present disclosure.

Permanent connection methods include gluing or spot-welding, dependingon the cap material. Alternatively, these elements may be permanentlysealed with a high-strength adhesive, such as epoxy. To form a singlecomponent, the EMR cap assembly may be made of a single component thatincludes a resection loop channel merging into a track parallel to itsdistal opening. The EMR cap may be formed as a single component bymolding, lithography or any other suitable manufacturing technique.

The diameter of EMR cap assembly 100 may be configured to match therequirements of particular applications. In general, a uniform diameteralong the length of the device may be preferred for most applications.In situations where tissues are small or when the body cavity is verynarrow, a tapered EMR cap assembly may be preferred Conversely, flaredor tapered EMR cap assemblies, may be utilized when the tissues arelarge or the body cavity is wide.

In some embodiments, EMR cap assembly 100 may change states between acollapsed and an expanded state. For example, while advancing aresecting device in the patient's body, EMR cap assembly 100 may assumea collapsed state, and when the device reaches the cancerous site,end-EMR cap assembly 100 may expand for operation. Expandable devicesare well known in the art and require no further elaboration here. Forexample, end-EMR cap assembly 100 may be formed of distinct longitudinalsections joined to each other by flexible members such as rubber,spring, or elastic. Flexible members allow the distinct sections toslide over each other in the collapsed state and abut each other in theexpanded state. EMR cap assembly 100 may also be made of any suitablesuper elastic or shape memory material, such as, for example, nitinol orshape memory polymers,

The following section describes a resection device that may implementthe EMR cap assembly 100 for conducting endoscopic mucosal resection.

Exemplary Resection Device

FIG. 5 is a perspective view of a resection device 500 for cutting andextracting an undesired mass through an incision or a natural bodyopening. The device 500 includes an elongate tube 502 with a distal end504, a proximal end 506, joined by a lumen 508. Proximal end 506 may becoupled to a handle 510, while distal end 504 is coupled to EMR capassembly 100. The tube further includes one or more internal channels(not shown) having proximal and distal end openings.

Tube 502 may have a cross-sectional configuration adapted according to adesired body lumen. In the illustrated embodiment, tube 502 may includea generally circular cross-section, with a generally circular hollowinterior lumen. Further, the tube 502 may have a uniform diameter or maybe tapered at the distal end to allow convenient insertion within thebody.

Depending upon the particular implementation and intended use, thelength of tube 502 may vary. For example, tube 502 may be a fewcentimeters or less where a shallow body cavity or organ is involved.For long cavities or deeper organs such as the bowel or intestine, tube502 may be relatively long. Similarly, depending upon the particularimplementation and intended use, the tube can be rigid along its entirelength, flexible along a portion of its length, or configured forflexure at only certain specified locations.

In one embodiment, tube 502 may be flexible, adapted for flexiblesteering within bodily lumens, as understood in the art. For example,tube 502 can be steered with controls to move at least a portion,generally distal end 504, up and down, or side-to-side. Additionaldegrees of freedom, provided for example via rotation, translationalmovement of tube 502, or additional articulation of bending sections,are also contemplated. In such an embodiment, resection device 500 maybe provided with suitable steering systems for, among other things,articulating or steering distal end 504 of tube. For example, a suitablesteering system may include one or more of pulleys, control wires,gearing, electrical actuators (such as servomotors), pneumaticactuators, and the like.

Such flexible tubes may be formed of any suitable material havingsufficient flexibility to traverse body cavities and tracts. Suitablematerials may include synthetic plastics, fiber, or polymers.Alternatively, tube 502 may be rigid or semi-rigid, formed frommaterials such as stainless steel or the like, including super elasticor shape memory alloys such as nitinol. Tube 502 may also bemanufactured from any biocompatible material such as a sheath, with orwithout a Teflon outer layer.

Moreover, the tube 502 and EMR cap assembly 100 may be designed toimpose minimum risk to the surrounding tissues while in use. To thisend, the proximal or distal ends of these components may includegeometrical structures, such as rounded or beveled terminal ends orfaces, to reduce trauma and irritation to surrounding tissues. Further,the outer surface of EMR cap assembly and tube may include any suitablecoating or covering. For example, the outer surface may include a layerof lubricous material to facilitate insertion through a body lumen orsurgical insertion.

To effectively maneuver the tube 502 within a body cavity, the operatorshould know the exact location of the tube in the cavity at all times.To this end, one or more portions of resection device 500 may beradiopaque, produced by inclusion of material such as barium sulfate inplastic material or one or more metal portions, which provide sufficientradiopacity. Alternatively, the distal end of the tube or EMR capassembly may include a radiopaque marker or sonoreflective marker (notshown). These markings facilitate detection of a position and/ororientation of tube 502 within the patient's body, and a surgeon, withthe aid of suitable imaging equipment, may track the path followed bythe endoscope system and avoid potential damage to sensitive tissues. Inother embodiments, device 500 is designed to fit through a workingchannel of an endoscopic device and may be observed through theendoscopic device. Alternatively, the device 500 may be deliveredadjacent to or over the endoscopic device.

To inhibit bacterial growth in the body cavity or in the mucosal wall,resection device 500 may be coated with an anti-bacterial coating. Thecoating may contain an inorganic antibiotic agent, disposed in apolymeric matrix, which adheres the anti-biotic agent to the device'ssurface. Further, a drug releasing coating may also be applied to theouter surface of resection device 500, assisting in healing. In furtherembodiments, resection device may be constructed from materialimpregnated with suitable antibiotic or therapeutic agents.

As discussed, tube 502 may include one or more channels. A typicalconfiguration may include a working channel and a resection loopchannel. Based on the application, other channels, such as a scopechannel or a camera channel, may also be present. Through thesechannels, the operator may introduce one or more medical devices toextend out of the distal end of tube 502. For example, during aresectomy, the operator may introduce a suction device into the workingchannel, and introduce a resection loop into the resection loop channel.Additionally, from time to time during the procedure, the operator mayinsert a light source, a camera, an injector, or a morcellator withinthe working channel. The distal ends of these channels may coincide withthe working channel and resection loop channel of EMR cap assembly 100while their proximal end may be coupled to the distal end of handle 510.In other embodiments, light sources and optics, such as a cameras may beintegrated into the walls of the tube. Optics may be integrated in thewall of the tube from the proximal end to the distal end. In otherembodiment, wireless optic means may be integrated only in the distalend walls of the tube.

The proximal end 506 of tube 502 can be coupled to handle 510 forgripping by an operator such as a surgeon, while the distal end 106remains open for medical devices to extend out. The handle 510 can beattached to tube 502 by, for example, welding, use of an adhesive, orintegrally forming with tube 502.

Handle 510 may include one or more ports 512 to introduce medicaldevices into the working channels of the tube. Moreover, vacuum pumps orirrigation feeds may be attached to port 512 to generate a suction forceat the distal end of the tube, or deliver irrigation fluid to thedesired location within a patient's body, respectively. Handle 510 mayinclude ability to steer the distal end of the resection device.Further, the handle portion may include an actuating mechanism toactuate one or more medical devices at the distal end of the elongatetube. For example, the handle may include an actuating mechanism toactuate and close the resection loop at the distal end of the resectiondevice. Similarly, it may include a mechanism to power on or off thesuction device attached to its working channel.

The EMR cap assembly 100 may be coupled to the distal end of the tube502. In one embodiment, the EMR cap assembly 100 may be detachablyattached to the distal end of the tube 502 using any known couplingtechnique such as snap-fitting, luer-lock, screw threading, etc. Beforeinserting the tube within a patient's body, the EMR cap assembly may besnapped on. Alternatively, the EMR cap assembly may be permanentlycoupled to the distal end of the tube. Techniques such as gluing,welding, or sealing may be used.

Further, a swivel mechanism may be introduced between the tube 502 andthe EMR cap assembly 100, such that the EMR cap assembly 100 may easilyswivel to make a greater surface contact with a lesion and swiveltowards the lesion. In some embodiments, the cap will swivel uponcontact with tissue to allow alignment of the opening of the cap. Inother embodiments, the cap may be controllably rotated for aligning thecap opening. Any suitable swivel mechanism may be used without departingfrom the scope of the present disclosure.

In other embodiments, the tube and the EMR cap assembly may be shapedsuch that the EMR cap assembly may be inserted into the lumen of thetube until it extends out from the distal end of the tube. Here, thediameter of the tube 502 and the EMR cap assembly 100 may taper from theproximal to the distal end, such that the distal diameter of the tube502 is lesser than the proximal diameter of the EMR cap assembly 100. Inthis situation, when the EMR cap assembly 100 is pushed to the distalend, its proximal portion engages with the distal opening of the tube,wedging it in place.

It will be understood that other techniques to engage the proximal endof the EMR cap assembly with the distal end of the elongate tube may becontemplated without departing from the scope of the present disclosure.For example, magnetic connection may be possible between the distal tubeopening and the proximal EMR cap assembly opening.

Exemplary Resection Method

FIGS. 6A-6F illustrates a method for resecting lesions or polyps ortissue from a patient's body. A typical location for a resection of thissort is the esophagus, and that location will be discussed here. As willbe understood by those in the art, other patient locations would beequally suitable. An endoscopic device including the cap assembly may beinserted into the body lumens either through a percutaneous incisionproviding access to the esophagus, or through a natural opening, such asthe mouth. Once inserted, the resection device 500 is advanced towards alocation on a mucosal wall 602. A light source and a camera may beinserted in the working channel to direct the device within theesophagus, and to spot the lesions. Alternatively, polyps and lesionsmay be identified by any suitable means prior to inserting resectiondevice 500 into the patient. Pedunculated polyps may be easilyidentified within the esophagus. Low-lying and flat lesions, however,may be harder to discover. To detect these lesions, a biomarker or dyemay be sprayed in the esophagus. Cancerous lesions emit a differentwavelength when light falls on them, allowing operators to easily detectthem.

In the illustrated embodiment, EMR cap assembly 100 is coupled to thedistal end of elongate tube 502 when the procedure begins.Alternatively, EMR cap assembly 100 may be actuated to extend out of thedistal end of the tube 502 when required. As shown, the distal end ofthe EMR cap assembly 100 may then be placed over or proximate a lesion604. In case the lesion is situated at an unreachable position withinthe body, EMR cap assembly 100 may swivel to attain contact with thelesion and/or surrounding tissue. This position is depicted in FIG. 6B.

The resection loop (not shown) may extend in an open or active stateinto track 112 when the EMR cap assembly 100 is extended. Next, asuction device is introduced into the working channel of the tube 502 toextend to the working channel 202 of the EMR cap assembly 100 unit. Thesuction device introduces suction force that draws the lesion 604 intothe working channel 202 of the EMR cap assembly 100 (FIG. 6C). In oneembodiment, if the lesion is too flat along the esophageal wall, thelesion may be injected with a saline solution or any other suitablesolution to create a buffer layer between the lesion and that wall. Withthe lesion sufficiently raised off the esophagus wall, suction may bemore easily accomplished.

Once the lesion 604 is forced into the working channel 202 of the EMRcap assembly 100, the proximal end of resection loop 402 may be pulledproximally, so that resection loop 402 begins closing by withdrawinginto track 112, reducing the resection loop's diameter in track 112, andtrapping lesion 604. Subsequent pulling may contract resection loop 402further, forming a tightened grip around lesion 604. This stage isillustrated in FIG. 6D.

In some embodiments, the suction device may be powered off or removed,and a telescope or microscope may be introduced in working channel 202along with a light device. The scope may closely examine lesion 604 todetermine whether it is cancerous or not. Various techniques may beemployed for this determination. In one embodiment, a fluorescent orbiomarker dye may be sprayed on lesion 604. If lesion 604 is cancerous,it will emit a particular color. Based on the emitted or projectedcolor, physicians can determine whether the lesion is benign orcancerous. Alternatively, by looking at lesion 604 under the microscope,physicians can make this decision.

If desired, an electro cautery device may be inserted in the workingchannel 202, or the resection loop itself may be a cauterizing resectionloop providing electrical energy to the trapped portion of the lesion604, and resecting it off the esophagus wall (as shown in FIG. 6E). Withmodifications in the EMR cap assembly 100 device, the electro-cauterydevice may be replaced with a laser device that resects the lesion. Insome embodiments, the cap itself may have electrocautery capability,such as electrodes in the cap. Other resecting means may becontemplated, which will lie within the scope of the present disclosure.

Once the lesion is resected, the device may carry out any one of anumber of procedures to remove the resected matter. For example, theresection device 500 may extract lesion 604 or morcellate it and thenextract it. For extraction, any retrieval device known now or later maybe employed. In one embodiment, the lesion 604 may be extracted with thehelp of suction force applied at the proximal end of the resectiondevice 500. In another embodiment, a basket, a grasper, or pincers maybe used. These devices may be self-expandable or may expand by someactuation mechanism incorporated in the resection device's handle 510.The retrieval device may be inserted in a collapsed state through theproximal end of the tube 502; and, it may extend out of the distal end106 of the EMR cap assembly's working channel 202 in an expanded state.Once the device is placed over the resected lesion, it may be actuatedto close in on the lesion, trapping it. Subsequently, the entireresection device 500 may be withdrawn from the patient's body. Inanother embodiment, the end of the inner cap may be flexible. Afterresection, the end of the cap may be actuated to close over the resectedlesion, trapping it and subsequently removing it from the patient'sbody.

If lesion 604 is too large to fit in working channel 202 or be graspedin the other retrieval tools, it may be morcellated prior to extraction.A morcellator (not shown) may be introduced in working channel 202 alongwith a suction device. The suction device holds lesion 604 around theopening of the EMR cap assembly 100, while the morcellator breaks lesion604 into smaller pieces. Subsequently, the retrieval devices suction orextract the pieces.

Embodiments of the present disclosure may be used in any medical ornon-medical procedure, including any medical procedure where monitoringof an organ's activity is desired. In addition, at least certain aspectsof the aforementioned embodiments may be combined with other aspects ofthe embodiments, or removed, without departing from the scope of thedisclosure.

Other embodiments of the present disclosure will be apparent to thoseskilled in the art from consideration of the specification and practiceof the embodiments disclosed herein. It is intended that thespecification and examples be considered as exemplary only, with a truescope and spirit of the invention being indicated by the followingclaims.

What is claimed is:
 1. A tissue resection device, comprising: an end capassembly, including: a first cap portion having a proximal end regionand a distal end region, a second cap portion having a proximal endregion, a distal end region terminating distally at a distalmost surfaceof the second cap portion, and an internal chamber, wherein the secondcap portion is received within the first cap portion such that theproximal end region of the first cap portion concentrically surroundsthe proximal end region of the second cap portion, and the distal endregion of the first cap portion concentrically surrounds the distalmostsurface of the second cap portion, and a channel extending between thefirst cap portion and the second cap portion, and opening into theinternal chamber of the second cap portion.
 2. The tissue resectiondevice of claim 1, wherein the channel is defined by a flexiblemembrane.
 3. The tissue resection device of claim 1, wherein the channelis movable between an expanded state and a contracted state.
 4. Thetissue resection device of claim 3, wherein the second cap portionincludes an interior wall surface defining the internal chamber, and thechannel contracts toward the interior wall surface when moving to thecontracted state.
 5. The tissue resection device of claim 3, wherein thesecond cap portion includes an interior wall surface defining theinternal chamber, and the channel expands away from the interior wallsurface when moving to the expanded state.
 6. The tissue resectiondevice of claim 1, wherein at least one of first cap portion and thesecond cap portion is movable between an expanded state and a contractedstate.
 7. The tissue resection device of claim 6, wherein the at leastone of the first cap portion and the second cap portion is formed oflongitudinally-extending sections, and the longitudinally-extendingsections are joined to one another by flexible members.
 8. The tissueresection device of claim 6, wherein the at least one of the first capportion and the second cap portion is formed of a shape memory material.9. The tissue resection device of claim 1, wherein the channel includesa proximal region and a distal region.
 10. The tissue resection deviceof claim 9, wherein the distal region of the channel extends between thefirst cap portion and the second cap portion.
 11. The tissue resectiondevice of claim 9, wherein the proximal region of the channel opens intothe internal chamber of the second cap portion.
 12. The tissue resectiondevice of claim 1, wherein the proximal end region of the first capportion terminates at a proximalmost surface of the first cap portion,the proximal end region of the second cap portion terminates at aproximalmost surface of the second cap portion, and the proximalmostsurface of the first cap portion is flush with the proximalmost surfaceof the second cap portion.
 13. A tissue resection device, comprising: anend cap assembly, including: a hollow outer cap portion having aninterior, a hollow inner cap portion having an exterior, wherein theinner cap portion is received by the outer cap portion such that theouter cap portion concentrically surrounds the inner cap portion and theinterior of the outer cap portion contacts the exterior of the inner capportion, and a channel defining a gag that extends between the exteriorof the inner cap portion and the interior of the outer cap portion. 14.The tissue resection device of claim 13, wherein the inner cap portionhas an interior defining a chamber, and the channel opens into thechamber, and the channel is external to the interior of hollow inner capportion.
 15. The tissue resection device of claim 14, wherein thechannel is movable between an expanded state and a contracted state. 16.The tissue resection device of claim 13, wherein at least one of theinner cap portion and the outer cap portion is movable between anexpanded state and a contracted state.
 17. A tissue resection device,comprising: an end cap assembly, including: an outer cap portion havinga radially-inward-facing surface, and an inner cap portion having afirst radially-outward-facing surface, and a secondradially-outward-facing surface recessed from the firstradially-outward-facing surface, wherein the inner cap portion isreceived by the outer cap portion such that the outer cap portionsurrounds the inner cap portion, the radially-inward-facing surface ofthe outer cap portion contacts the first radially-outward-facing surfaceof the inner cap portion, and the radially-inward-facing surface of theouter cap portion is spaced apart from the secondradially-outward-facing surface of the inner cap portion to form acavity between the inner cap portion and the outer cap portion.
 18. Thetissue resection device of claim 17, wherein the inner cap portionincludes an internal chamber, and the end cap assembly further includesa channel opening into the cavity and the internal chamber.
 19. Thetissue resection device of claim 18, wherein the channel is movablebetween an expanded state and a contracted state.
 20. The tissueresection device of claim 17, wherein at least one of inner cap portionand the outer cap portion is movable between an expanded state and acontracted state.